apt-pkg/depcache.h

   1 // -*- mode: c++; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: depcache.h,v 1.14 2001/02/20 07:03:17 jgg Exp $
   4 /* ######################################################################
   5
   6    DepCache - Dependency Extension data for the cache
   7
   8    This class stores the cache data and a set of extension structures for
   9    monitoring the current state of all the packages. It also generates and
  10    caches the 'install' state of many things. This refers to the state of the
  11    package after an install has been run.
  12
  13    The StateCache::State field can be -1,0,1,2 which is <,=,>,no current.
  14    StateCache::Mode is which of the 3 fields is active.
  15
  16    This structure is important to support the readonly status of the cache
  17    file. When the data is saved the cache will be refereshed from our
  18    internal rep and written to disk. Then the actual persistant data
  19    files will be put on the disk.
  20
  21    Each dependency is compared against 3 target versions to produce to
  22    3 dependency results.
  23      Now - Compared using the Currently install version
  24      Install - Compared using the install version (final state)
  25      CVer - (Candidate Verion) Compared using the Candidate Version
  26    The candidate and now results are used to decide wheather a package
  27    should be automatically installed or if it should be left alone.
  28
  29    Remember, the Candidate Version is selected based on the distribution
  30    settings for the Package. The Install Version is selected based on the
  31    state (Delete, Keep, Install) field and can be either the Current Version
  32    or the Candidate version.
  33
  34    The Candidate version is what is shown the 'Install Version' field.
  35
  36    ##################################################################### */
  37                                                                         /*}}}*/
  38 #ifndef PKGLIB_DEPCACHE_H
  39 #define PKGLIB_DEPCACHE_H
  40
  41
  42 #include <apt-pkg/pkgcache.h>
  43 #include <apt-pkg/progress.h>
  44
  45 #include <regex.h>
  46
  47 #include <vector>
  48 #include <memory>
  49 #include <set>
  50
  51 class pkgDepCache : protected pkgCache::Namespace
  52 {
  53    public:
  54
  55    /** \brief An arbitrary predicate on packages. */
  56    class InRootSetFunc
  57    {
  58    public:
  59      virtual bool InRootSet(const pkgCache::PkgIterator &pkg) {return false;};
  60      virtual ~InRootSetFunc() {};
  61    };
  62
  63    private:
  64    /** \brief Mark a single package and all its unmarked important
  65     *  dependencies during mark-and-sweep.
  66     *
  67     *  Recursively invokes itself to mark all dependencies of the
  68     *  package.
  69     *
  70     *  \param pkg The package to mark.
  71     *
  72     *  \param ver The version of the package that is to be marked.
  73     *
  74     *  \param follow_recommends If \b true, recommendations of the
  75     *  package will be recursively marked.
  76     *
  77     *  \param follow_suggests If \b true, suggestions of the package
  78     *  will be recursively marked.
  79     */
  80    void MarkPackage(const pkgCache::PkgIterator &pkg,
  81                     const pkgCache::VerIterator &ver,
  82                     bool const &follow_recommends,
  83                     bool const &follow_suggests);
  84
  85    /** \brief Update the Marked field of all packages.
  86     *
  87     *  Each package's StateCache::Marked field will be set to \b true
  88     *  if and only if it can be reached from the root set.  By
  89     *  default, the root set consists of the set of manually installed
  90     *  or essential packages, but it can be extended using the
  91     *  parameter #rootFunc.
  92     *
  93     *  \param rootFunc A callback that can be used to add extra
  94     *  packages to the root set.
  95     *
  96     *  \return \b false if an error occurred.
  97     */
  98    bool MarkRequired(InRootSetFunc &rootFunc);
  99
 100    /** \brief Set the StateCache::Garbage flag on all packages that
 101     *  should be removed.
 102     *
 103     *  Packages that were not marked by the last call to #MarkRequired
 104     *  are tested to see whether they are actually garbage.  If so,
 105     *  they are marked as such.
 106     *
 107     *  \return \b false if an error occurred.
 108     */
 109    bool Sweep();
 110
 111    public:
 112
 113    // These flags are used in DepState
 114    enum DepFlags {DepNow = (1 << 0),DepInstall = (1 << 1),DepCVer = (1 << 2),
 115                   DepGNow = (1 << 3),DepGInstall = (1 << 4),DepGCVer = (1 << 5)};
 116
 117    // These flags are used in StateCache::DepState
 118    enum DepStateFlags {DepNowPolicy = (1 << 0), DepNowMin = (1 << 1),
 119                        DepInstPolicy = (1 << 2), DepInstMin = (1 << 3),
 120                        DepCandPolicy = (1 << 4), DepCandMin = (1 << 5)};
 121
 122    // These flags are used in StateCache::iFlags
 123    enum InternalFlags {AutoKept = (1 << 0), Purge = (1 << 1), ReInstall = (1 << 2)};
 124
 125    enum VersionTypes {NowVersion, InstallVersion, CandidateVersion};
 126    enum ModeList {ModeDelete = 0, ModeKeep = 1, ModeInstall = 2};
 127
 128    /** \brief Represents an active action group.
 129     *
 130     *  An action group is a group of actions that are currently being
 131     *  performed.  While an active group is active, certain routine
 132     *  clean-up actions that would normally be performed after every
 133     *  cache operation are delayed until the action group is
 134     *  completed.  This is necessary primarily to avoid inefficiencies
 135     *  when modifying a large number of packages at once.
 136     *
 137     *  This class represents an active action group.  Creating an
 138     *  instance will create an action group; destroying one will
 139     *  destroy the corresponding action group.
 140     *
 141     *  The following operations are suppressed by this class:
 142     *
 143     *    - Keeping the Marked and Garbage flags up to date.
 144     *
 145     *  \note This can be used in the future to easily accumulate
 146     *  atomic actions for undo or to display "what apt did anyway";
 147     *  e.g., change the counter of how many action groups are active
 148     *  to a std::set of pointers to them and use those to store
 149     *  information about what happened in a group in the group.
 150     */
 151    class ActionGroup
 152    {
 153        pkgDepCache &cache;
 154
 155        bool released;
 156
 157        /** Action groups are noncopyable. */
 158        ActionGroup(const ActionGroup &other);
 159    public:
 160        /** \brief Create a new ActionGroup.
 161         *
 162         *  \param cache The cache that this ActionGroup should
 163         *  manipulate.
 164         *
 165         *  As long as this object exists, no automatic cleanup
 166         *  operations will be undertaken.
 167         */
 168        ActionGroup(pkgDepCache &cache);
 169
 170        /** \brief Clean up the action group before it is destroyed.
 171         *
 172         *  If it is destroyed later, no second cleanup wil be run.
 173         */
 174        void release();
 175
 176        /** \brief Destroy the action group.
 177         *
 178         *  If this is the last action group, the automatic cache
 179         *  cleanup operations will be undertaken.
 180         */
 181        ~ActionGroup();
 182    };
 183
 184    /** \brief Returns \b true for packages matching a regular
 185     *  expression in APT::NeverAutoRemove.
 186     */
 187    class DefaultRootSetFunc : public InRootSetFunc
 188    {
 189      std::vector<regex_t *> rootSetRegexp;
 190      bool constructedSuccessfully;
 191
 192    public:
 193      DefaultRootSetFunc();
 194      ~DefaultRootSetFunc();
 195
 196      /** \return \b true if the class initialized successfully, \b
 197       *  false otherwise.  Used to avoid throwing an exception, since
 198       *  APT classes generally don't.
 199       */
 200      bool wasConstructedSuccessfully() const { return constructedSuccessfully; }
 201
 202      bool InRootSet(const pkgCache::PkgIterator &pkg);
 203    };
 204
 205    struct StateCache
 206    {
 207       // Epoch stripped text versions of the two version fields
 208       const char *CandVersion;
 209       const char *CurVersion;
 210
 211       // Pointer to the candidate install version.
 212       Version *CandidateVer;
 213
 214       // Pointer to the install version.
 215       Version *InstallVer;
 216
 217       // Copy of Package::Flags
 218       unsigned short Flags;
 219       unsigned short iFlags;           // Internal flags
 220
 221       /** \brief \b true if this package can be reached from the root set. */
 222       bool Marked;
 223
 224       /** \brief \b true if this package is unused and should be removed.
 225        *
 226        *  This differs from !#Marked, because it is possible that some
 227        *  unreachable packages will be protected from becoming
 228        *  garbage.
 229        */
 230       bool Garbage;
 231
 232       // Various tree indicators
 233       signed char Status;              // -1,0,1,2
 234       unsigned char Mode;              // ModeList
 235       unsigned char DepState;          // DepState Flags
 236
 237       // Update of candidate version
 238       const char *StripEpoch(const char *Ver);
 239       void Update(PkgIterator Pkg,pkgCache &Cache);
 240
 241       // Various test members for the current status of the package
 242       inline bool NewInstall() const {return Status == 2 && Mode == ModeInstall;};
 243       inline bool Delete() const {return Mode == ModeDelete;};
 244       inline bool Keep() const {return Mode == ModeKeep;};
 245       inline bool Upgrade() const {return Status > 0 && Mode == ModeInstall;};
 246       inline bool Upgradable() const {return Status >= 1;};
 247       inline bool Downgrade() const {return Status < 0 && Mode == ModeInstall;};
 248       inline bool Held() const {return Status != 0 && Keep();};
 249       inline bool NowBroken() const {return (DepState & DepNowMin) != DepNowMin;};
 250       inline bool NowPolicyBroken() const {return (DepState & DepNowPolicy) != DepNowPolicy;};
 251       inline bool InstBroken() const {return (DepState & DepInstMin) != DepInstMin;};
 252       inline bool InstPolicyBroken() const {return (DepState & DepInstPolicy) != DepInstPolicy;};
 253       inline bool Install() const {return Mode == ModeInstall;};
 254       inline VerIterator InstVerIter(pkgCache &Cache)
 255                 {return VerIterator(Cache,InstallVer);};
 256       inline VerIterator CandidateVerIter(pkgCache &Cache)
 257                 {return VerIterator(Cache,CandidateVer);};
 258    };
 259
 260    // Helper functions
 261    void BuildGroupOrs(VerIterator const &V);
 262    void UpdateVerState(PkgIterator Pkg);
 263
 264    // User Policy control
 265    class Policy
 266    {
 267       public:
 268
 269       virtual VerIterator GetCandidateVer(PkgIterator Pkg);
 270       virtual bool IsImportantDep(DepIterator Dep);
 271
 272       virtual ~Policy() {};
 273    };
 274
 275    private:
 276    /** The number of open "action groups"; certain post-action
 277     *  operations are suppressed if this number is > 0.
 278     */
 279    int group_level;
 280
 281    friend class ActionGroup;
 282
 283    protected:
 284
 285    // State information
 286    pkgCache *Cache;
 287    StateCache *PkgState;
 288    unsigned char *DepState;
 289
 290    double iUsrSize;
 291    double iDownloadSize;
 292    unsigned long iInstCount;
 293    unsigned long iDelCount;
 294    unsigned long iKeepCount;
 295    unsigned long iBrokenCount;
 296    unsigned long iPolicyBrokenCount;
 297    unsigned long iBadCount;
 298
 299    bool DebugMarker;
 300    bool DebugAutoInstall;
 301
 302    Policy *delLocalPolicy;           // For memory clean up..
 303    Policy *LocalPolicy;
 304
 305    // Check for a matching provides
 306    bool CheckDep(DepIterator Dep,int Type,PkgIterator &Res);
 307    inline bool CheckDep(DepIterator Dep,int Type)
 308    {
 309       PkgIterator Res(*this,0);
 310       return CheckDep(Dep,Type,Res);
 311    }
 312
 313    // Computes state information for deps and versions (w/o storing)
 314    unsigned char DependencyState(DepIterator &D);
 315    unsigned char VersionState(DepIterator D,unsigned char Check,
 316                               unsigned char SetMin,
 317                               unsigned char SetPolicy);
 318
 319    // Recalculates various portions of the cache, call after changing something
 320    void Update(DepIterator Dep);           // Mostly internal
 321    void Update(PkgIterator const &P);
 322
 323    // Count manipulators
 324    void AddSizes(const PkgIterator &Pkg,signed long Mult = 1);
 325    inline void RemoveSizes(const PkgIterator &Pkg) {AddSizes(Pkg,-1);};
 326    void AddStates(const PkgIterator &Pkg,int Add = 1);
 327    inline void RemoveStates(const PkgIterator &Pkg) {AddStates(Pkg,-1);};
 328
 329    public:
 330
 331    // Legacy.. We look like a pkgCache
 332    inline operator pkgCache &() {return *Cache;};
 333    inline Header &Head() {return *Cache->HeaderP;};
 334    inline PkgIterator PkgBegin() {return Cache->PkgBegin();};
 335    inline GrpIterator FindGrp(string const &Name) {return Cache->FindGrp(Name);};
 336    inline PkgIterator FindPkg(string const &Name) {return Cache->FindPkg(Name);};
 337    inline PkgIterator FindPkg(string const &Name, string const &Arch) {return Cache->FindPkg(Name, Arch);};
 338
 339    inline pkgCache &GetCache() {return *Cache;};
 340    inline pkgVersioningSystem &VS() {return *Cache->VS;};
 341
 342    // Policy implementation
 343    inline VerIterator GetCandidateVer(PkgIterator Pkg) {return LocalPolicy->GetCandidateVer(Pkg);};
 344    inline bool IsImportantDep(DepIterator Dep) {return LocalPolicy->IsImportantDep(Dep);};
 345    inline Policy &GetPolicy() {return *LocalPolicy;};
 346
 347    // Accessors
 348    inline StateCache &operator [](PkgIterator const &I) {return PkgState[I->ID];};
 349    inline unsigned char &operator [](DepIterator const &I) {return DepState[I->ID];};
 350
 351    /** \return A function identifying packages in the root set other
 352     *  than manually installed packages and essential packages, or \b
 353     *  NULL if an error occurs.
 354     *
 355     *  \todo Is this the best place for this function?  Perhaps the
 356     *  settings for mark-and-sweep should be stored in a single
 357     *  external class?
 358     */
 359    virtual InRootSetFunc *GetRootSetFunc();
 360
 361    /** \return \b true if the garbage collector should follow recommendations.
 362     */
 363    virtual bool MarkFollowsRecommends();
 364
 365    /** \return \b true if the garbage collector should follow suggestions.
 366     */
 367    virtual bool MarkFollowsSuggests();
 368
 369    /** \brief Update the Marked and Garbage fields of all packages.
 370     *
 371     *  This routine is implicitly invoked after all state manipulators
 372     *  and when an ActionGroup is destroyed.  It invokes #MarkRequired
 373     *  and #Sweep to do its dirty work.
 374     *
 375     *  \param rootFunc A predicate that returns \b true for packages
 376     *  that should be added to the root set.
 377     */
 378    bool MarkAndSweep(InRootSetFunc &rootFunc)
 379    {
 380      return MarkRequired(rootFunc) && Sweep();
 381    }
 382
 383    bool MarkAndSweep()
 384    {
 385      std::auto_ptr<InRootSetFunc> f(GetRootSetFunc());
 386      if(f.get() != NULL)
 387        return MarkAndSweep(*f.get());
 388      else
 389        return false;
 390    }
 391
 392    /** \name State Manipulators
 393     */
 394    // @{
 395    void MarkKeep(PkgIterator const &Pkg, bool Soft = false,
 396                  bool FromUser = true, unsigned long Depth = 0);
 397    void MarkDelete(PkgIterator const &Pkg, bool Purge = false,
 398                    unsigned long Depth = 0, bool FromUser = true);
 399    void MarkInstall(PkgIterator const &Pkg,bool AutoInst = true,
 400                     unsigned long Depth = 0, bool FromUser = true,
 401                     bool ForceImportantDeps = false);
 402
 403    void SetReInstall(PkgIterator const &Pkg,bool To);
 404    void SetCandidateVersion(VerIterator TargetVer);
 405
 406    /** Set the "is automatically installed" flag of Pkg. */
 407    void MarkAuto(const PkgIterator &Pkg, bool Auto);
 408    // @}
 409
 410    /** \return \b true if it's OK for MarkInstall to install
 411     *  the given package.
 412     *
 413     *  See the default implementation for a simple example how this
 414     *  method can be used.
 415     *  Overriding implementations should use the hold-state-flag to cache
 416     *  results from previous checks of this package - also it should
 417     *  be used if the default resolver implementation is also used to
 418     *  ensure that these packages are handled like "normal" dpkg holds.
 419     *
 420     *  The parameters are the same as in the calling MarkInstall:
 421     *  \param Pkg       the package that MarkInstall wants to install.
 422     *  \param AutoInst  needs a previous MarkInstall this package?
 423     *  \param Depth     recursive deep of this Marker call
 424     *  \param FromUser  was the install requested by the user?
 425     */
 426    virtual bool IsInstallOk(const PkgIterator &Pkg,bool AutoInst = true,
 427                             unsigned long Depth = 0, bool FromUser = true);
 428
 429    /** \return \b true if it's OK for MarkDelete to remove
 430     *  the given package.
 431     *
 432     *  See the default implementation for a simple example how this
 433     *  method can be used.
 434     *  Overriding implementations should use the hold-state-flag to cache
 435     *  results from previous checks of this package - also it should
 436     *  be used if the default resolver implementation is also used to
 437     *  ensure that these packages are handled like "normal" dpkg holds.
 438     *
 439     *  The parameters are the same as in the calling MarkDelete:
 440     *  \param Pkg       the package that MarkDelete wants to remove.
 441     *  \param Purge     should we purge instead of "only" remove?
 442     *  \param Depth     recursive deep of this Marker call
 443     *  \param FromUser  was the remove requested by the user?
 444     */
 445    virtual bool IsDeleteOk(const PkgIterator &Pkg,bool Purge = false,
 446                             unsigned long Depth = 0, bool FromUser = true);
 447
 448    // read persistent states
 449    bool readStateFile(OpProgress *prog);
 450    bool writeStateFile(OpProgress *prog, bool InstalledOnly=false);
 451
 452    // Size queries
 453    inline double UsrSize() {return iUsrSize;};
 454    inline double DebSize() {return iDownloadSize;};
 455    inline unsigned long DelCount() {return iDelCount;};
 456    inline unsigned long KeepCount() {return iKeepCount;};
 457    inline unsigned long InstCount() {return iInstCount;};
 458    inline unsigned long BrokenCount() {return iBrokenCount;};
 459    inline unsigned long PolicyBrokenCount() {return iPolicyBrokenCount;};
 460    inline unsigned long BadCount() {return iBadCount;};
 461
 462    bool Init(OpProgress *Prog);
 463    // Generate all state information
 464    void Update(OpProgress *Prog = 0);
 465
 466    pkgDepCache(pkgCache *Cache,Policy *Plcy = 0);
 467    virtual ~pkgDepCache();
 468
 469    private:
 470    // Helper for Update(OpProgress) to remove pseudoinstalled arch all packages
 471    bool RemovePseudoInstalledPkg(PkgIterator &Pkg, std::set<unsigned long> &recheck);
 472 };
 473
 474 #endif